Render objects to separate files using python
Wrote my first lines of Python to answer this.

It is pretty straight forward.  The assumptions for this script to work is that
1) all you objects are on the first (0th) layer
2) you have selected the objects you want rendered.

import bpy

selected = bpy.context.selected_objects

for obj in selected:
    obj.layers[19]=True
    obj.layers[0]=False
index = 0
for obj2 in selected:
    obj2.layers[0]=True
    obj2.layers[19]=False
    print(index);
    bpy.data.scenes["Scene"].render.filepath = '/ur/path/here/render_%d.jpg' % index
    bpy.ops.render.render( write_still=True )
    obj2.layers[19]=True
    obj2.layers[0]=False
    index+=1
for obj in selected:
    obj.layers[0]=True
    obj.layers[19]=False


This code simply first moves all the selected objects from the first to the last layer. Then, one by one, moves each object back to first layer, renders it into a unique file, then moves back to last layer.  Lastly, moves all objects back to the original layer.

Note: on OS X to render into your Documents folder the path would look something like '/Users/username/Documents/render_%d.jpg'.